Vehicles and trains are powered with drive systems which can use electric energy converters. There is a market demanding low cost, efficient and reliable converters. In a known system, power-electronic components, such as discrete or integrated (i.e. module type) semiconductor devices, inductors, resistors, capacitors and copper bus-bars, can be assembled in close proximity. During operation, these components can dissipate heat of varying quantities. In addition, these components are tolerant to temperatures of varying levels. Temperature conditions can differ depending on which area of the world the converters are used in. The thermal management and integration concept of a drive system can also consider humidity and other factors in addition to the electrical performance of the system.
The design of trains utilizes equipment which can be arranged on the roof of the train or underneath the floor (for example, in an underfloor converter). Semiconductor components and power resistors can be heat sources of traction converters. They can be built with a plate-mount design to be bolted or pressed onto a flat surface that is kept at a suitably low, relatively cold temperature. Fan-blown-air cooled aluminum heat sinks and pumped water cooled cold plates are examples of a heat exchange surface. Other components such as inductors, capacitors and PCB circuit elements can be cooled by air-flow.
One possibility for achieving environmental protection is to arrange critical electric circuits, including semiconductor components, in protected enclosures. However, removal of heat can get more complicated with higher protection of the components.
The degree of environmental protection that is offered by an electronic product can be expressed in terms of its “Ingress Protection (IP) Rating.” Many drive products are offered in IP20 or IP21 as standard with IP54 or higher protection ratings offered as optional. With lower IP ratings it is possible to design for through-flow of outside air within the drive enclosure while still providing adequate protection. Air filters can be employed to reduce the particles in the air. Down-facing air-vents on the enclosure walls can prevent vertical water droplets from entering. With higher IP ratings, however, separation of outside air from the inside air of the drive enclosure becomes desirable. For the highest protection levels, like IP65 or even more, a water-tight enclosure can become desirable.
An air-to-air heat-exchanger can be employed in high IP rated enclosures in order to dissipate heat to the ambient while separating the cabinet internal and external air volumes. Heat-pipes and thermoelectric cooling elements can also be used in such devices.
EP2031332 shows a heat exchanger using air cooling. The device disclosed in EP2031332 is a thermosyphon heat exchanger for traction converters. However, the Ingress Protection offered by the disclosed system is still limited. Furthermore, there exists a need for a more compact and more efficient system to cool heat sources of the power modules of a train.